It delivered a specific capacitance of 2,099 F g −1 in cyclic-voltammetry tests at 1 mV s −1 and 2,049 F g −1 in galvanostatic charge–discharge tests at 1.5 A g −1 . The same optimized composition also degraded pollutants more rapidly under UV irradiation than pristine nickel zincate and the 3% Fe-doped material. Structural and spectroscopic studies confirmed that iron was incorporated into the nickel zincate lattice.

The doping was accompanied by crystallite refinement and defect formation. UV–visible spectroscopy showed that the band gap decreased gradually as the iron concentration increased. The supplied study abstract reports these structural, optical and electrochemical observations together, but it does not establish a direct causal link between the band-gap change and either the capacitance or the photocatalytic performance.

The findings concern a laboratory material evaluation rather than a demonstrated treatment system for a specific wastewater stream. Electrochemical impedance measurements showed lower solution resistance after iron incorporation: 1.844 Ω for Fe–NiZnO 2 , compared with 2.64 Ω for pristine NiZnO 2 . The researchers built an asymmetric device using Fe–NiZnO 2 and activated carbon.

At a current density of 2 A g −1 , the device achieved a specific capacitance of 281 F g −1 , an energy density of 97.6 Wh kg −1 and a power density of 1,600 W kg −1 . It also maintained cycling stability over 10,000 cycles. These measurements characterize the reported laboratory device; the abstract does not provide additional details about retention percentages, operating conditions, manufacturing scale or performance in commercial cells.

For the environmental application, the optimized 5% Fe–NiZnO 2 catalyst showed rapid degradation of pollutants under UV-light irradiation in comparison with pristine nickel zincate and the 3% Fe-doped counterpart. The result indicates that the 5% composition performed better than the lower-doped material in the reported test conditions. The abstract does not identify the pollutants, concentrations, catalyst loading, irradiation conditions, analytical method or mineralization efficiency, so the result supports faster degradation under the study’s conditions without establishing complete mineralization or performance across different wastewater compositions.

Taken together, the findings present Fe–NiZnO 2 nanostructures as a material family tested for both high-power energy storage and UV-driven photocatalytic wastewater remediation.

Subject of Research: Laboratory evaluation of iron-doped nickel zincate for supercapacitors and UV photocatalytic pollutant degradation.

Article Title: Iron-doped nickel zincate nanostructures for high-performance supercapacitors and enhanced photocatalytic wastewater remediation

Article References: Kamran, M. A., Sattar, S., Alhabradi, M., Suhaima, Afzal, A. M., & Tahir, M. (2026). Iron-doped nickel zincate nanostructures for high-performance supercapacitors and enhanced photocatalytic wastewater remediation. Journal of Materials Science, 61(40), 31145-31167. https://doi.org/10.1007/s10853-026-13689-6

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13689-6

Keywords: iron-doped nickel zincate, supercapacitors, photocatalysis, wastewater remediation, energy storage, nanostructured materials, electrochemical impedance, activated carbon, UV degradation, Iron-doped, nickel, zincate